A new fossil survey has revealed cephalopods like this early squid were ruling the seas over 500 million years ago. This is far earlier than previously believed. Meet Nectocaris pteryx, the ancient predator with two tentacles.

Though researchers had seen fossils of the Nectocaris pteryx before, a recent survey of new fossils found in British Columbia, Canada, made it clear that these two-tentacled creatures are in fact the precursors of the ten-tentacled squid of today. Evolutionary biologist Martin Smith describes the find in an article published this afternoon in Nature.

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From a release about the article:

The new specimens, between two and five centimetres long, show that Nectocaris was kite-shaped and flattened from top to bottom, with large, stalked eyes and a long pair of grasping tentacles, which the researchers believe helped it to hunt for and consume prey. Smith and [Jean-Bernard] Caron further suggest that the creature swum using its large lateral fins, and, like modern cephalopods, probably used its nozzle-like funnel to accelerate by jet propulsion. "Some of the specimens' large gills were choked with mud, suggesting that the animals were fossilized after being caught in an underwater mud-flow," says Smith.

"Our findings mean that cephalopods originated 30 million years earlier than we thought, and much closer to the first appearance of complex animals in the 'Cambrian explosion'" says Smith. Nectocaris does not have a mineralized shell, a fact that surprised the scientists. "It's long been thought that cephalopods evolved in the Late Cambrian period, when gradual modifications to the shells of creeping, snail-like animals made them able to float. Nectocaris shows us that the first cephalopods actually started swimming without the aid of gas-filled shells. Shells evolved much later, probably in response to increased levels of competition and predation in the Late Cambrian."